Skis conventionally are made to be used in a variety of snow conditions encountered on ski slopes, ranging from loose powder to ice. Typically, skis have a structure which includes a central structural core, often made of composite materials, to which lateral metallic edges are attached. The skis typically have sidecut contours shaped, e.g., in the form of a parabola, and when the ski is rotated about its longitudinal axis by the skier the edges dig into and grip the snow and cause the ski, and skier, to turn and thereby maneuver down the ski slope. In known fashion, the bottom surfaces of the lateral edges are often ground at a small angle to the bottom of the ski and/or slightly dulled to promote a slight skid and to prevent the skier from “catching an edge” and losing control.
A problem with conventional ski structures has arisen in that in icy conditions or hard-packed snow conditions edging becomes difficult: if the ski is not held at a very precise angle to the surface with proper angulation and weighting, the edges do not dig in and grip the surface to cause a turn, but instead slide across the ice or snow with an accompanying loss of control that may cause the skier to fall or collide with another skier or obstruction. Icy conditions sometimes are widespread, but often they occur intermittently on slopes in areas that receive heavy traffic, and thus changing the edge grind is rarely a practical solution to this problem.
Ski designers and manufacturers have attempted to maximize edging capabilities while at the same time developing and refining the other handling and performance characteristics of their skis. Ski design parameters which affect how a ski will hold an edge on hard snow or ice are camber, sidecut, stiffness, damping and torsional rigidity. These characteristics all affect edging, but they are strongly interrelated and also affect a ski's overall performance and other handling parameters. Thus edging capability has been seen as but one design element intertwined with other performance characteristics and incapable of being enhanced independently.
Accordingly, there is a need to provide a ski structure that is able to provide improved edging characteristics, especially in hard or icy conditions, but also is able to retain its ability to perform well in a variety of other snow conditions. There is a need to provide a ski design that effectively separates the ski's edging function from the ski's other performance and handling characteristics. There is a further need for a ski that allows skiers of modest ability and strength to edge effectively, and that allows skiers of great ability, such as racers, to edge effectively in high speed or severe slope conditions. Additionally, there remains a need to provide a ski structure and ski-making method that allows skis to be made simply and economically, and that at the same time assist the skier to edge the skis properly in icy conditions.